Pregnant women may get safer HIV protection with tailored PrEP doses

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: Maternal participants: * Aged 16 years or older * PrEP-eligible by local guidelines * Pregnant with a viable singleton pregnancy of between 14 and 23 completed weeks of gestation (from 14 weeks + 0 days to 23 weeks + 6 days) by ultrasonography at study entry * HIV-negative based on the study-specific screening algorithm * Hepatitis B surface antigen (HBsAg)-negative * Weight \>35 kg * Provided informed consent and expressed willingness to participate in study activities with their infants, including daily administration of oral PrEP under direct observation Infant participants: Infant participants enter the study with their mother as unborn infants. There are no specific eligibility criteria for infant participation otherwise. If an infant is deemed too ill to undergo study procedures, procedures necessary for clinical management may be prioritized. Exclusion Criteria: Maternal participants will not enter the study if any of the following conditions are identified during the screening process: * Grade 2 or greater laboratory parameters for alanine transaminase (ALT) or aspartate aminotransferase (AST), hemoglobin (HB), and absolute neutrophil count (ANC). * Estimated creatinine clearance (CrCl) 90 mL/min or below, using the Cockcroft-Gault formula. * Known history or evidence of current significant disease process, including: hematological conditions, renal disease, unexplained bone fractures, environmental enteric dysfunction, or allergies/sensitivities to FTC/TDF. * Other current significant or uncontrolled disease process (active or chronic), substance use, or social circumstances that, in the judgment of the site investigator, would make participation in the study inappropriate or unsafe. * Fetuses with known or suspected major fetal anomaly, either from screening ultrasound or via medical record * Intention to leave the study site's catchment area before scheduled study exit. * Current use of prohibited medications * Concurrent use of other biomedical HIV prevention interventions (vaginal ring, injectable PrEP, any investigational prevention product).